1. Chapter 10-11 Review

2. The Heart: Heart Wall Slide 11.4 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Three layers  Epicardium  Outside layer  This layer is the parietal pericardium  Connective tissue layer  Myocardium  Middle layer  Mostly cardiac muscle  Endocardium  Inner layer  Endothelium

3. The Heart: Coverings Slide 11.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Pericardium – a double serous membrane  Visceral pericardium  Next to heart  Parietal pericardium  Outside layer  Serous fluid fills the space between the layers of pericardium

4. The Heart: Chambers Slide 11.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Right and left side act as separate pumps  Four chambers  Atria  Receiving chambers (thinner walls)  Right atrium  Left atrium  Ventricles  Discharging chambers  Right ventricle (2nd thickest)  Left ventricle (thickest)

5. The Cardiovascular System 2. Blood Vessels -A network of tubes – Arteries  arterioles move away from the heart Elastic Fibers Circular Smooth Muscle – Capillaries – where gas exchange takes place. One cell thick Serves the Respiratory System – Veins  Venules moves towards the heart Skeletal Muscles contract to force blood from legs back to heart One way leaflet valves – When the valves no longer meet properly (valvular incompetence) varicose veins form b/c of pooling blood/ backflow

6. 6 Regulation of the Heart Intrinsic regulation: Results from normal functional characteristics—initiated by heart’s own pacemaker nodes, not on neural or hormonal regulation – Starling’s law of the heart-- stroke volume of the heart increases in response to an increase in the volume of blood filling the heart (the end diastolic volume) when all other factors remain constant (more blood in the heart=stronger heart muscular contraction) stroke volumeend diastolic volume Extrinsic regulation: Involves neural and hormonal control – Parasympathetic stimulation (by medulla oblongata) Supplied by vagus nerve, decreases heart rate, acetylcholine secreted – Sympathetic stimulation Supplied by cardiac nerves, increases heart rate and force of contraction, epinephrine and norepinephrine released

7. Heart Homeostasis Effect of blood pressure – Baroreceptors monitor blood pressure Effect of pH, carbon dioxide, oxygen – Chemoreceptors monitor Effect of extracellular ion concentration – Increase or decrease in extracellular K + decreases heart rate Effect of body temperature – Heart rate increases when body temperature increases, heart rate decreases when body temperature decreases

9. 9 Arteries: Built for their job Arteries – blood flows away from heart – thicker walls provide strength for high pressure pumping of blood – elastic & stretchable maintains blood pressure even when heart relaxes

10. 10 Major arteries pulmonary artery pulmonary artery = to lungs aorta carotid = to head to brain & left arm to right arm coronary arteries to body

11. Veins: Built for their job Veins – blood returns back to heart – thinner-walled blood travels back to heart at low speed & pressure why low pressure? – far from heart blood flows because muscles contract when we move – squeeze blood through veins – valves in large veins in larger veins one-way valves allow blood to flow only toward heart Open valve Blood flows toward heart Closed valve

12. 12 Structure-function relationship Capillaries – very thin walls – allows diffusion of materials across capillary O 2, CO 2, H 2 O, food, waste body cell O2O2 food waste CO 2

13. 13 Blood Vessels: Anatomy Slide 11.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Three layers (tunics)  Tunic intima  Endothelium  Tunic media  Smooth muscle  Controlled by sympathetic nervous system  Tunic externa  Mostly fibrous connective tissue

14. 2 part system – Circulation to lungs (pulmonary) blood gets O 2 from lungs) drops off CO 2 to lungs brings O 2 -rich blood from lungs to heart – Circulation to body (systemic) pumps O 2 -rich blood to body picks up nutrients from digestive system collects CO 2 & cell wastes Circulation of Blood lungs body Circulation to lungs Circulation to body

15. 15 Vertebrate circulatory system lungs body 2 part system artery to body artery to lungs vein from lungs to heart vein from body to heart

16. 16 Pathway of the blood PULMONARY (deoxygenated) Superior/ Inferior Vena Cava Right Atrium Tricuspid Valve Right Ventricle Pulmonary Semilunar Valve Lungs Pulmonary arteries SYSTEMIC pulmonary veins Left Atrium Bicuspid Valve Left Ventricle Aortic Semilunar Valve Aorta To the body’s organs & cells

17. 17 Cardiac Muscle Elongated, branching cells containing 1-2 centrally located nuclei Contains actin and myosin myofilaments Intercalated disks: Specialized cell-cell contacts Desmosomes hold cells together and gap junctions allow action potentials Electrically, cardiac muscle behaves as single unit

18. Conducting System of Heart

19. Refractory Period Absolute: Cardiac muscle cell completely insensitive to further stimulation Relative: Cell exhibits reduced sensitivity to additional stimulation Long refractory period prevents tetanic contractions

20. Electrocardiogram Action potentials through myocardium during cardiac cycle produces electric currents than can be measured Pattern – P wave Atria depolarization – QRS complex Ventricle depolarization Atria repolarization – T wave: Ventricle repolarization

21. EKG Interpretation P-wave – SA node sends signal through atria muscle – Atria depolarize (becomes more positive) P

22. Conducting System of Heart

23. EKG Interpretation P-wave – Graph Result: small upward curve – Result: Current passes over Atria P

24. EKG Interpretation P  Q segment – Graph Result: Flat line – Response: Atrial contraction time P Q

25. EKG Interpretation QRS complex (or interval) – AV node sends signal through ventriclular muscle – Ventricles depolarize (change charge sign) Q R S P

26. EKG Interpretation QRS complex – Response: Current passes over ventricles Q R S P

27. EKG Interpretation S  T segment – Graph: rise, flat line and bump – Response: Ventricular contraction time Q R S P T

28. EKG Interpretation T-wave – Ventricles repolarize – Response: Return to resting potential Q R S P T

29. EKG Interpretation U-wave (if present) – Repolarization of papillary muscles Q R S P TU

30. Heart Sounds First heart sound or “lub” – Atrioventricular (AV) valves close at beginning of ventricular systole (contraction) Second heart sound or “dub” – Results from closure of aortic and pulmonary semilunar valves at beginning of ventricular diastole (relaxation) Third heart sound (occasional) – Caused by turbulent blood flow into ventricles and detected near end of first one-third of diastole

31. Pulse Slide 11.35 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Pulse – pressure wave of blood  Monitored at “pressure points” where pulse is easily palpated Figure 11.16

32. Blood Vessels: Anatomy Slide 11.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Three layers (tunics)  Tunic intima  Endothelium  Tunic media  Smooth muscle  Controlled by sympathetic nervous system  Tunic externa  Mostly fibrous connective tissue

33. Plasma Proteins Slide 10.4 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Albumin – regulates osmotic pressure  Clotting proteins – help to stem blood loss when a blood vessel is injured  Antibodies – help protect the body from antigens

34. Platelets Slide 10.13 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Derived from ruptured multinucleate cells (megakaryocytes)  Needed for the clotting process  Normal platelet count = 300,000/mm 3

35. Platelet Plug Formation Slide 10.19 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Collagen fibers are exposed by a break in a blood vessel  Platelets become “sticky” and cling to fibers  Anchored platelets release chemicals to attract more platelets  Platelets pile up to form a platelet plug

36. pump (peak pressure) _________________ fill (minimum pressure) Cardiac Cycle How is this reflected in blood pressure measurements? chambers fill ventricles fill ventricles pump systolic ________ diastolic 110 ________ 80

37. 37 Cardiac Cycle Heart is two pumps that work together, right and left half Repetitive contraction (systole) and relaxation (diastole) of heart chambers Blood moves through circulatory system from areas of higher to lower pressure. – Contraction of heart produces the pressure

38. Cardiac Cycle